Fluid cooling means for rotors of rotary mechanisms



Sept. 14, 1965 HANNS-DIETER PASCHKE 3,206,109

FLUID COOLING MEANS FOR ROTOR-S OF ROTARY MECHANISMS Filed Feb. 12, 1964s Sheets-Sheet 1 INVENTOR HANNEI-DIETER F'AEIEHKE ATT E1 Sept. 14, 1965HANNS-DIETER PASCHKE 3,205,109

FLUID COOLING MEANS FOR ROTORS 0F ROTARY MECHANISMS Filed Feb. 12, 19645 Sheets-Sheet 2 INVENTOR HANNEl-DIETER F'AEEHKE BY I S Q ATTDRNEY p1955 HANNS-DIETER PASCHKE 3,206,109

FLUID COOLING MEANS FOR ROTORS OF ROTARY MECHANISMS Filed Feb. 12, 19645 SheetsSheet 3 INVENTOR HANNE-DIETER PAEEHKE ATTDRNEY Se t. 14, 1965HANNS-DIETER PASCHKE 3, 06,

FLUID COOLING MEANS FOR ROTORS OF ROTARY MECHANISMS Filed Feb. 12, 19645 Sheets-Sheet 4 INVENTOR HANNEl-D lliTElFi F'AEIEHKE BY l g ATTURNEYSept. 14, 1965 HANNS-DIETER PASCHKE 3,

FLUID COOLING MEANS FOR ROTORS OF ROTARY MECHANISMS Filed Feb. 12, 19645 Sheets-Sheet 5 INVENTOR HANN'Ex-DIETER F'AEJEHKE ATTORNEY UnitedStates Patent 3,206,109 FLUID COOLING MEANS FOR ROTORS 0F ROTARYMECHANISMS Harms-Dieter Paschke, Neckarsulm, Wurttemberg, Germany,assignor to NSU Motorenwerke Alrtiengesellschaft, Neclrarsulm, Germany,and Wankel G.m.b.H., Lindau (Bodensee), Germany Filed Feb. 12, 1964,Ser. No. 344,396 Claims priority, application Germany, Mar. 7, 1963, N22,853 Claims. (CL 230-410) This invention relates to rotary mechanismshaving fluid cooling means for the rotors of said mechanisms and inparticular to an improved means for circulating the cooling fluidthrough said rotor.

The present invention is directed to improvement in the fluid coolingmeans described in US. Patent 3,102,682, issued on September 3, 1963 andassigned to the same assignee as the present invention. As explained insaid patent, the rotor of the rotary mechanism is mounted so as torotate on a rotating eccentric and makes a planetary circulatingmovement relative to the external housing or outer body. By thisarrangement the rotor is acted upon by acceleration forces whichperiodically reverse in direction and therefore any cooling liquidwithin the rotor and movable therewith is subject to the same periodicreversal of the acceleration forces. The rotor of the present inventionis provided with a plurality of separate circumferentially-spacedinternal compartments with openings for supplying and draining thecooling fluid from said compartments. When the acceleration forces on aparticular rotor compartment are directed radially outwardly the coolingliquid is thrown into said compartments through an inlet opening andupon reversal of the acceleration forces the cooling liquid is thrownradially inwardly and out of the outlet opening of said compartment. Asthe coolant flows out of the outlet opening it can be collected forrecirculation through the interior of the rotor after suitable removalof the heat from the cooling fluid.

It has been found in a construction of the type illustrated by theaforementioned patent, that a considerable amount of cooling fluid isrequired for maintaining the circulation of the cooling fluid throughthe rotor. Due to the relatively rapid circulation of the cooling fluidthrough the rotor in the above described construction, the effective useof the fluid for cooling during a single pass through a coolingcompartment is not completely utilized and therefore it will be apparentthat the amount of cooling fluid circulated through the rotor is greaterthan necessary.

The present invention has for its prime object providing means forreducing the amount of cooling medium circulated through the interior ofthe rotor while maintaining maximum cooling effectiveness of the rotorinterior walls. The invention is generally carried out by providing aplurality of circumferentially spaced cooling compartments in theinterior of the rotor and providing openings thereto for supplying anddraining the cooling fluid with said openings being so located withrespect to the direction of the circulating fluid, when the accelerationforces acting on a particular rotor compartment are directed radiallyinwardly, the cooling fluid within the rotor compartment will not becompletely drained from 3,206,109 Patent-ed Sept. 14, 1965 saidcompartment but some of said cooling fluid will be mixed with incomingcooling fluid so as to increase the volume of cooling fluid availablefor cooling the rotor Walls. By this means the total volume of oilwithin each rotor compartment will be maintained without requiring atotal increase in the volume of oil required for circulation through theentire rotor interior.

Accordingly, it is an object of the invention to provide a novel andimproved cooling means for the interior of the rotor in a rotarymechanism.

It is another object of the invention to provide a novel and improvedfluid cooling means for the interior of a rotor in a rotary mechanismwherein the amount of cooling fluid required for cooling said rotorinterior is substantially reduced over previous constructions havingcooling means for r-otor interiors.

It is an additional object of the invention to provide a novel andimproved means for supplying and draining cooling fluid from theinterior of the rotor in a rotary mechanism.

Other objects and advantages of the invention will become apparent uponreading the following detailed description of the invention with theaccompanying drawings wherein;

FIG. 1 is an axial sectional view of a rotary mechanism embodying theinvention,

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1 anddiagrammatically illustrating the cooling fluid in the coolingcompartments,

FIGS. 3-8 are views similar to FIG. 2 and diagrammatically illustratingthe oil circulation in portions of the interior rotor at differentstates of rotor rotation, and

FIG. 9 is an axial sectional view of the rotary mechanism illustratinganother embodiment of the invention.

Referring now to FIGS. 1 and 2, there is shown therein a rotarymechanism being preferably in the form of a rotary combustion enginealthough the invention may be embodied in other types of rotarymechanisms such as fluid pumps, fluid motors or the like. The rotarymechanism 10 is composed of an outer body including a pair of end walls12 and 14 interconnected by a peripheral wall 16 to form a cavitytherein. The profile of the inner surface 18 of the outer bodyperipheral Wall 16 is preferably basically a two-lobed epitrochoid (FIG.2). A shaft 20 is mounted coaxially with the cavity formed by the outerbody and is rotatable relative to said outer body. The shaft 20 has aneccentric portion 22 formed thereon upon which is rotatably mounted arotor 24 having a multilobed profile and whose outer peripheral wall 26forms a plurality of circumferentially-spaced apex portions for sealingengagement with the inner surface 18 of the outer body peripheral wall16. Preferably, as illustrated, the rotor has three apex portions andthe multilobed cavity of the outer body has two-lobed portions althoughother combinations are possible. Seal strips 28 are provided in each ofthe apex portions of the rotor 24 and extend from one end face of therotor to the other end face and are in continuous sealing engagementwith the inner surface 18 of the outer body peripheral wall 16 to form aplurality of working chambers 30 which during relative rotation vary involume. The apex seals 28 mate with intermediate seal bodies 32 alsoprovided in each of the apex portions of the rotor and with side seals34 provided in each of the end walls 36 and 38, re-

spectively, to provide a continuous seal adjacent the periphery of therotor and on each side thereof.

As further illustrated, the rotor 26 is supported on the eccentricportion 22 by a sleeve-type bearing 40. Suitable bearings 42 are alsoprovided for supporting the rotating shaft 20 in the outer body housingand surrounding bearings 42 on one side of the mechanism is anexternally toothed gear 44 which meshes with an internally toothed gear46 either supported by the rotor end wall 36 or made integral with aportion of said end wall 36. The gears 42 and 44 serve to help rotatablyposition the rotor with respect to the epitrochoidal surface of theperipheral wall 16 but do not drive or impart torque to the shaft 20. Inthe embodiment illustrated having a two-lobed epitrochoid and athree-lobed rotor, the ratio of rotation of the shaft with respect tothe rotor is 3:1 wherein for each rotation of the rotor about is axisthe shaft rotates three times about its axis with the axes of the shaftand rotor being designated as M M in FIG. 2, respectively. An intakeport 48 is provided for admitting air and/or a fuel-air mixture, anignition means 50 may be provided for igniting the mixture and anexhaust port 52 is provided for expelling the burnt gases so that thestages of intake, compression, expansion and exhaust may be carried out.

In order to supply a cooling fluid for cooling the interior walls of therotor, an inlet passageway 54 may be provided in the end wall 12 of theouter body and may be suitably connected to a pump and fluid reservoir(not shown) for pumping the fluid through a passageway 54 and into anannular cavity 56 between the rotor and the housing end wall 12. Asfurther illustrated in the drawings, particularly with reference to FIG.2, the rotor 24 is made hollow and is provided with a plurality ofaxially-extending interior walls or partitions 60 with said partitions69 being circumferentially-spaced around the rotor 24 to divide therotor interior into a plurality of cirumferentially-spaced coolingcompartments 58. The partitions 69 extend in an avial direction from oneend wall 36 of the rotor to the opposite end wall 38 and in a radialdirection from the rotor peripheral wall 26 radially inward to the rotorhub or the radially interior wall 62 of the rotor. In order to supplythe cooling fluid to the interior of the rotor or to the rotorcompartment 58 an inlet passageway 64 is provided in the wall 36 of therotor and has an inlet opening 66 to each of the compartments 58. Anoulet passageway 68 for each compartment is provided in the end wall 38of the rotor and has an outlet opening '79 communicating with theinterior of each compartment 58. As will be explained in greater detailbelow, the relationship between the inlet opening 66 and the outletopenings 70 for each rotor compartment 58 with respect to the rotor endwalls 36 and 38 is significant to the operation of the invention.

During relative rotation of the rotor 24 and the eccentric portion 22,acceleration forces are generated which act substantially in thedirection of maximum eccentricity of the eccentric portion 22. As willbe apparent from FIG. 2, with the acceleration forces acting radiallyoutwardly with respect to some of the rotor compartments, 'or upwardlyin said FIG. 2, any fluid present in the annular cavity 56 or in therotor compartment will be thrown radially outwardly in response to theacceleration forces and the fluid on the opposite side of the mechanismor the downward side will be thrown radially inwardly with respect tothe rotor compartments 58. As the rotor rotates relative to the outerbody, the acceleration forces will periodically change direction withrespect to said rotor. Therefore, with respect to the rotor compartments58 it will be seen that the acceleration forces successively changedirection and that at one instant the fluid will be acted upon byradially outwardly directed forces and that at another instant the fluidwill be acted upon by the radially inwardly directed forces. Duringoperation of the mechanism, the fluid present in the cavity 56 willtherefore be thrown radially outward into the inlet passageway 64 andout of the inlet passageway opening 66 to the compartments 58 and duringa reversal of the direction of the acceleration forces the fluid in thecompartments 58 will then be thrown radially inwardly and into theoutlet opening 70 and out of the outlet passageway 68 and will draininto an annular collection scoop member 72 to which is connected anoutlet passageway 74 in the outer body end wall 14 for draining thefluid out of the rotary mechanism and to a suitable cooling means. Thecooling fluid may then be recirculated through the rotor so that thesame cooling fluid may be used over again. Annular seals 76 are providedbetween each of the rotor end walls 36 and 38 and the housing end walls12 and 14, respectively, to prevent leakage of the cooling fluidradially outwardly into the working chambers 30 of the rotary mechanism.

In the prior embodiments of cooling fluid mechanisms for the interior ofrotors in rotary mechanisms the relationship between the inlet andoutlet openings for the rotor compartments was such that when thecooling fluid was acted upon by radially inwardly directed accelerationforces substantially all of the cooling fluid in a rotor compartment wasdrained out of said compartment. During the filling portion of the cycletherefore a relatively large amount of cooling fluid was then requiredto refill the compartment in order to provide maximum effective cooling.It will be apparent that in these systems a relatively large totalamount of cooling fluid is required in order to provide for thesubstantially complete exchange of the cooling fluid in each of thecompartments. The present invention, however, overcomes thisdisadvantage by providing a relationship between the inlet and outletopenings for each compartment wherein the cooling fluid is notcompletely drained from each compartment so that a lesser amount isrequired during the filling cycle portion which therefore results in alesser total amount of cooling fluid being required to maintain maximumcooling of the rotor interior. With reference to FIG. 1, it will be seenthat the inlet opening 66 and the outlet opening 70 are disposed so thatthey are spaced radially outwardly a substantial distance from theradially innermost portion of their respective rotor compartment 58. Bythis means, when the acceleration forces are directed radially inwardlyfor draining the cooling fluid from the compartments 58, some of thecooling fluid will drain through the inlet opening 66 into thepassageway 64 where it will mix with supply fluid from the annularcavity 56 which is at a slightly higher pressure due to the pump supplythrough the passageway 54 and therefore at least a portion of thecooling fluid will be prevented from draining from the compartments 58.During the draining portion of the cycle, as a result of the location ofthe inlet opening 66 and the outlet opening 70, a residual amount ofcooling fluid will be left in each of the rotor compartments 58 belowthe level of said inlet opening 66 and said outlet opening 70.Therefore, there will always be some cooling fluid remaining in therotor compartments for circulation over the walls thereof and a lesseramount of cooling fluid will be required to fill each of said rotorcompartments during the filling portion of the cycle.

Referring now to FIGS. 2-8, as seen therein, theoutlet openings 70 aredisposed so that they are spaced from the partitions 60 in acircumferential direction and spaced from the rotor peripheral wall 26and the rotor inner wall 62 in a radial direction. Although not shown insaid figures, the openings 66 for supplying cooling fluid to thecompartments 58 are similarly disposed with respect to the compartmentwalls of said compartments'SS. As described above, this arrangementresults in a residual amount of cooling fluid remaining behind in eachchamher during the drainage portion of the cycle. This occurs becausesome of the cooling fluid will be thrown radially inwardly beyond theopenings 66 and 70 and will not drain from the compartments since atthis time the out let and inlet opening will be radially outward fromthis portion of the cooling fluid. It will be apparent that this wouldnot be the case if the inlet and outlet openings 66 and 70 were disposedso that they were adjacent the most radially inward portion of thecompartment. Again referring to FIGS. 2-8, the circulation of thecooling fluid in the rotary compartments 58 is diagrammaticallyillustrated for different stages of rotor rotation. In FIG. 2 twocompartments 58a and 58b are shown at a stage of rotation wherein suchcompartments are substantially at the position of maximum eccentricityof the shaft rotation and the cooling fluid therein is shown during thesupply phase. The cooling fluid at this time is thrown into saidcompartments and collects adjacent the inner surface the rotorperipheral Wall 26. In FIGS. 3 and 4 the cooling fluid will be seen asrotating around the inner surfaces of the walls of the compartment 58 inthe direction of rotor rotation until when the rotor has reached theposition shown in FIG. 5 wherein the point of maximum eccentricity ofthe shaft is opposite to the compartments 58a and 58b, the cooling fluidwill then be thrown radially inwardly at which time a major portion ofthe cooling fluid will be drained out through the opening 70 and aportion through the opening 66. However, it will be noted that aresidual amount of cooling fluid will remain in the compartments 58a and58b even when the acceleration forces are directed radially inward, asillustrated. While FIG. 2 shows the supply phase of the compartments 58aand 58b, FIG. 5 shows the drainage phase of such compartments. Aspreviously stated the cooling fluid circulates around the interior wallsof the compartments in the direction of rotor rotation so that thesurfaces will be cooled by the contact with the cooling fluid. Theresidual quantity of fluid remaining in the compartments 58a and 5812will, during further rotation of the rotor, wash over the surfaces ofthe compartments 58a and 58b and thereby cool the surfaces until a newsupply of cooling fluid is supplied as shown in FIGS. 7 and 8. It willalso be apparent that these surfaces would not be cooled during thisportion of rotation of the rotor if the compartments were completelyemptied during this phase of rotor rotation illustrated in FIG. 5. Itwill be understood that each of the compartments of the rotor operatesin the same manner as the compartments 58a and 5811 which are used onlyas examples.

FIG. 9 shows a second embodiment of the invention which is substantiallyidentical to the embodiment illustrated in FIG. 1 and bears similarnumeral designations. However, in the embodiment of FIG. 9 at least someof the compartments 58' have no outlet passageway 68 and outlet openings70' so that during the drainage phase of the cycle, any drainage fromthese compartments will have to flow back through the inlet opening 66'.Therefore, a greater amount of residual cooling fluid will remain inthese compartments and that which drains out of these compartments willmix with the incoming supply of cooling fluid from the cooling supplycavity 56'. It should be understood however, that some of thecompartments must be provided with outflow openings 70 as in theembodiment of FIG. 1, to provide for a complete exchange of the coolingfluid during operation of the mechanism.

From the above description it will be seen that a novel and improvedcooling mechanism is provided for the interior of the rotor in a rotarymechanism. By use of the mechanism of the invention a substantiallysmaller amount of cooling fluid is required to cool the rotor in teriorwhile still maintaining maximum cooling effectiveness. Further, throughthe present invention, it is possible not only to use a smaller quantityof cooling fluid but the invention also has the advantage that a smallersupply reservoir, cooling recirculating mechanism and oil pump may beused which reduces the weight of the entire cooling unit.

While the invention has been specifically set forth in its preferredembodiments in the above description, it will be obvious to thoseskilled in the art, after understanding the invention, that variouschanges and modifications may be made therein without departing from thespirit or scope thereof. It is intended in the appended claims to coverall such modifications.

What is claimed is:

1. A rotary mechanism having an outer body comprising a peripheral wallinterconnected with a pair of parallel end walls defining a cavity; arotatable shaft mounted in said outer body coaxial with the axis of saidouter body peripheral wall and having an eccentric portion; a rotorrotatably supported on said eccentric portion for rotation about itsaxis while describing a planetary motion relative to the axis of saidouter body peripheral wall whereby acceleration forces are generated insaid rotor which successively change direction relative to said rotor,said rotor having a hub portion and a peripheral wall interconnectedwith a pair of parallel end walls defining a cavity therein with saidcavity having a plurality of circumferentially-spaced, axially-extendingpartitions dividing said cavity into a plurality of compartments overthe entire circumference thereof; an inlet opening for each of saidcompartments in one of said rotor end walls for supplying a coolingliquid to each said compartment when the acceleration forces aredirected substantially radially outwardly relative to each saidcompartment, said inlet opening being disposed in the region of theradially inner portion of its associated compartment but spaced radiallyoutwardly a substantial distance from the radially innermost portion ofsaid compartment; and a single outlet opening for at least some of saidcompartments in the other of said rotor end walls for draining coolingliquid from said compartments when the acceleration forces are directedsubstantially radially inwardly relative to said compartments, and saidoutlet opening being disposed closer to the radially innermost portionof its compartment than its radially outer portion but spaced radiallyoutwardly a substantial distance from the radially innermost portion ofits compartment such that at least some of said cooling liquid willdrain through said inlet opening for mixture with a fresh supply ofcooling liquid for said rotor compartment.

2. A rotary mechanism as recited in claim 1 wherein said inlet openingand said outlet opening are circumferentially-spaced from the partitionsforming each said com partment so that due to the spacing of saidopenings relative to the walls of said compartments a residual amount ofcooling liquid will remain in each said compartment after the remainderof said cooling liquid is drained through said openings.

3. A rotary mechanism as recited in claim 1 wherein each of said rotorcompartments is provided with an inlet and an outlet opening.

4. A rotary mechanism as recited in claim 1 wherein said inlet andoutlet openings are disposed substantially at the same level withrespect to said rotor end walls.

5. A rotary mechanism having an outer body comprising a peripheral wallinterconnected with a pair of parallel end walls defining a cavity; arotatable shaft mounted in said outer body coaxial with the axis of saidouter body peripheral wall and having an eccentric portion; a rotorrotatably supported on said eccentric portion for rotation about itsaxis while describing a planetary motion relative to the axis of saidouter body peripheral wall whereby acceleration forces are generated insaid rotor which successively change direction relative to said rotor,said rotor having a hub portion and a peripheral wall interconnectedwith a pair of parallel end Walls defining a cavity therein with saidcavity having a plurality of circumferentially-spaced, axially-extendingpartitions dividing said cavity into a plurality of compartments overthe entire circumference thereof; an inlet opening for each of saidcompartments in one of said rotor end walls for supplying a coolingliquid to each said compartment when the acceleration forces aredirected substantially radially outwardly relative to each saidcompartment, and a single outlet opening for at least some of saidcompartments in the other of said rotor end Walls for draining coolingliquid from said compartments when the acceleration forces are directedsubstantially radially inwardly relative to said compartments, saidinlet opening and said outlet opening being disposed closer to theradially innermost portion of its compartment than its radially outerportion but spaced radially outwardly from the radially innermostportion of their compartment and being spaced from the partitionsforming said compartment such that a resid- References Cited by theExaminer UNITED STATES PATENTS 9/63 Paschke 2302l0 X 12/63 Bentele230-210 10 LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner.

1. A ROTARY MECHANISM HAVING AN OUTER BODY COMPRISING A PERIPHERAL WALLINTERCONNECTED WITH A PAIR OF PARALLEL END WALLS DEFINING A CAVITY; AROTATABLE SHAFT MOUNTED IN SAID OUTER BODY COAXIAL WITH THE AXIS OF SAIDOUTER BODY PERIPHERAL WALL AND HAVING AN ECCENTRIC PORTION; A ROTORROTATABLY SUPPORTED ON SAID ECCENTRIC PORTION FOR ROTATION ABOUT ITSAXIS WHILE DESCRIBING A PLANETARY MOTION RELATIVE TO THE AXIS OF SAIDOUTER BODY PERIPHERAL WALL WHEREBY ACCELERATION FORCES ARE GENERATED INSAID ROTOR WHICH SUCCESSIVELY CHANGE DIRECTION RELATIVE TO SAID ROTOR,SAID ROTOR HAVING A HUB PORTION AND A PERIPHERAL WALL INTERCONNECTEDWITH A PAIR OF PARALLEL END WALLS DEFINING A CAVITY THEREIN WITH SAIDCAVITY HAVING A PLURALITY OF CIRCUMFERENTIALLY-SPACED, AXIALLY-EXTENDINGPARTITIONS DIVIDING SAID CAVITY INTO A PLURALITY OF COMPARTMENTS OVERTHE ENTIRE CIRCUMFERENCE THEREOF; AN INLET OPENING FOR EACH OF SAIDCOMPARTMENTS IN ONE OF SAID ROTOR END WALLS FOR SUPPLYING A COOLINGLIQUID TO EACH SAID COMPARTMENT WHEN THE ACCELERATION FORCES AREDIRECTED SUBSTANTIALLY RADIALLY OUTWARDLY RELATIVE TO EACH SAIDCOMPARTMENT, SAID INLET OPENING BEING DISPOSED IN THE REGION OF THERADIALLY INNER PORTION OF ITS ASSOCIATED COMPARTMENT BUT SPACED RADIALLYOUTWARDLY A SUBSTANTIAL DISTANCE FROM THE RADIALLY INNERMOST PORTION OFSAID COMPARTMENT; AND A SINGLE OUTLET OPENING FOR AT LEAST SOME OF SAIDCOMPARTMENTS IN THE OTHER OF SAID ROTOR END WALLS FOR DRAINING COOLINGLIQUID FROM SAID COMPARTMENTS WHEN THE ACCELERATION FORCES ARE DIRECTEDSUBSTANTIALLY RADIALLY INWARDLY RELATIVE TO SAID COMPARTMENTS, AND SAIDOUTLET OPENING BEING DISPOSED CLOSER TO THE RADIALLY INNERMOST PORTIONOF ITS COMPARTMENT THAN ITS RADIALLY OUTER PORTION BUT SPACED RADIALLYOUTWARDLY A SUBSTANTIAL DISTANCE FROM THE RADIALLY INNERMOST PORTION OFITS COMPARTMENT SUCH THAT AT LEAST SOME OF SAID COOLING LIQUID WILLDRAIN THROUGH SAID INLET OPENING FOR MIXTURE WITH A FRESH SUPPLY FORCOOLING LIQUID FOR SAID ROTOR COMPARTMENT.